[PATCH] arm64: fix a migrating irq bug when hotplug cpu

Yang Yingliang
2015-08-29T13:02:10Z

From: Yang Yingliang <yangyingliang@huawei.com>

When cpu is disabled, all irqs will be migratged to another cpu.
In some cases, a new affinity is different, it needed to be coppied
to irq's affinity. But if the type of irq is LPI, it's affinity will
not be coppied because of irq_set_affinity's return value.
So copy the affinity, when the return value is IRQ_SET_MASK_OK_DONE.

Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
arch/arm64/kernel/irq.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 463fa2e..2acc8ec 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -78,10 +78,13 @@ static bool migrate_one_irq(struct irq_desc *desc)
}

c = irq_data_get_irq_chip(d);
- if (!c->irq_set_affinity)
+ if (!c->irq_set_affinity) {
pr_debug("IRQ%u: unable to set affinity\n", d->irq);
- else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK &&
ret)
- cpumask_copy(irq_data_get_affinity_mask(d), affinity);
+ } else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK
&& ret) {
+ int r = c->irq_set_affinity(d, affinity, false);
+ if ((r == IRQ_SET_MASK_OK || r == IRQ_SET_MASK_OK_DONE) && ret)
+ cpumask_copy(irq_data_get_affinity_mask(d), affinity);
+ }

return ret;
}
--
2.5.0